High Speed Steel Straight Flute "Hand Taps" are the most popular and versatile style of taps in general machine tapping operations. They are for general use in production tapping or hand operations in a wide range of application material groups. Taper - 7-10 pitch chamfer length. Starts the thread square with the workpiece Plug - 3-5 pitch chamfer length. Generally used in through holes Bottoming - 1-2 pitch chamfer length. Generates the thread to the bottom Sets - Contains 1 each of Taper, Plug, and Bottoming. Hish Speed Steel Hand Taps are availabile in imperial and metric sizes.